It's been a while but I think the references for Ezekiel Dennis and his wife are from David K. Faux's "Understanding Ontario First Nations Genealogical Records", and that might also be the reference for her background as Delaware. Faux went through hundreds of original Six Nations documents at the Archives, recording all references he found to white men with Six Nations wives, and his book also contains a list / chart that includes at least the Dochstaders and perhaps also the Dennises ( a few years ago he donated his remaining notes on Loyalists and their Six Nations wives to the Haldimand County Museum in Cayuga, where they can be searched by appointment ). Many assignments of Nation and clan that genealogists use when working with the Six Nations and with allied Nations like the Delaware and Tutelo are based on inference, e.g. children belong to the Nation and clan of their mother, so that if you can find primary reference to a descendant being "Delaware", "Onondaga" etc, on a Six Nations band roll or applying for status in that Nation, this would indicate that the clan and Nation of his / her mother, grandmother, great-grandmother, etc was the same. In the case of the Dennises I think there were several references of this type to indicate that Ezekiel's wife ( recorded as Julen in his will, so probably Julianne or Julia, a name her granddaughters also had ) was Delaware. This would fit well, since Ezekiel Dennis was a Quaker from New Jersey and New Jersey Quakers often had Delaware wives ( less often Iroquois wives, since historically the League resided Upper New York State ). The Delaware ( a.k.a. Lenape, Unami, Munsee ) were the original Algonquian inhabitants of New Jersey and Eastern Pennsylvania; a large contingent of them were later adopted as 'nephews' by the League of the Six Nations ( Iroquois ) and settled with them on the Grand River.
I went looking for Ezekiel Dennis back in the day but was not able to find much on him back in New Jersey. What I do remember is that there is a large Quaker Dennis family to which he seems to belong, and also that there were two men from that family both named Ezekiel Dennis who came to Upper Canada. Often, where Ezekiel Dennis of Long Point ( the one we're looking for ) is actually assigned ancestors, he is assigned the parents of the other Ezekiel Dennis of Upper Canada, which makes for some confusion. At best I think Ezekiel of Long Point's father might have been known and covered in one of the larger Dennis family genealogies ( I browsed these online at one point ), but his actual year and town of birth and mother's name I have never come across. New Jersey genealogy is the hardest to do for lack of records, and many of my older lines have gone back to that state only to disappear.
There are a large number of Julian families that settled early in Ontario but almost all of them are unrelated. My line is originally from Almonte near Ottawa and was one of the later arrivals, from London England and before that Norfolk.